Slidable supports



Sept. 1l, 1956 J. J. sLoYAN SLIDABLE SUPPORTS 5 Sheets-Sheet l.

Filed April 26, 195l W wa. ma MU W m .J

ATTORNEY Sept. 11, 1956 J, J, sLoYAN 2,762,662

SLIDABLE SUPPORTS Filed April 26, 1951 5 sheets-sheet 2 INVENTR fifa/Vf JT Zyq/Y.

f ATTQRNEY Sept. 11, 1956 J. J. sLoYAN 2,752,552

SLIDABLE SUPPORTS Filed April 2e, 1951 5 sheets-sheet s 3y INVENTOR .ff/WM5 JMW/y. 45 u BY M ATTORNEY Sept. 11, 1956 J. J. sLoYAN SLIDABLE SUPPORTS Filed April 26, 1951 5 Sheets-Sheet 4 WW2/01M ATTORNEY Sept. 1l, 1956 J. J. sLoYAN I 2,762,562

SLIDABLE SUPPORTS Filed April 26, 1951 5 Sheets-Sheet 5 .sill

l lNvENToR L BY o l 96 #mM/r W 9'/ ATTORNEY Unid States '2,762,662' sLIDigBLE SUPPORTS if Jerome J.' Sloyan', Bloomfield, N. J. Application April 2o, 1951, serial No. 223,034 1o Claims.l (Cl. '30soy This' invention is a continuation in partv and improvement upon the invention disclosed ini my. prior" ap'pllc'- tion Serial No. 117,999, tiled September 27, 1949, for supports, and, like the parent case, relates to slidable lsupports wherein a carriageis provided having a limited movement longitudinally of a' track or rail.

The invention has utility in association with various irfstrumentalities" of diverse character o'f' which' a' r'rlo'tor support has been' arbitrarily selected for" purpose of spe'cio'Y showing' in the accompanying' drawings. 'Il' essential characteristic of the' supportof' tle'preisentin; ventio11 c'ommon to thehumerous' uses, is `thatthe mow able portion of the' carriage has linear' movei'entwlthii maximum limits and must' slide with min'imu'rri-fict'ion throughout the prescribed range' of its permitte'd're'c'ip rooation. The mechanism includes, and an object'of'the invention is to provide an improved glider-` mountedwiith interposed' anti-friction'me'ans onl the trackor raihand'the present invention further contemplates use of av glider formedsepara'tely fromv the body oftiie' carria'ge ai'd boltedthereto in the assembled' support.`

Another object of the invention is' to obtaiiitight clamping of'the cross-members of they carriagefto the gliders and yet to maintain free operation of. thei'gllder under conditions'of tight clamping ofthe cro'ssmembe'rs thereto.

The invention proposes fulfillment of its'olijectiv: with use of materials available on the market and' yet to' obtain therewith exactitude of inter-engagement of tlparts of the" as s'erribly.4

A s'tilll further object of -the invention is to provide for controlled fluid pressure activation of the carriage.

Yet another object of the invention is to .not only yutilize materials of preff'abricated character, such as rectangular tubing, channels, I-beamsand the like, but to minimize additional fabrication operations in organizing tl'ef assembly; and to utilize readily performedprocessing for such fabrication operations' as required;

other objects vor* the invention will Becoine'apparent 'to persons skillediinwth'e" art to' which it' app'ertaisfa's the description proceeds, both'by direct recitationtli'erof l'and by implication" from thecontle'xt.

Referring to the accompanying'drawingg'in 'which'lil'ce numerals 'of reference iridica'te'simil'ar paitsthrollg'lut theseveral'views:

Figifl is ai'sidev elevation of'my' invention'o'r'l' Whit:v lis ca'rried a' motor havingibelt drive" to adriven ins rui mentality;

Fig? 3' is aj'longitudi'nal: sectional elvatio'n"or1"li"'re ICC 2 Figs 4 and 5 are cross-sections on lines I'V-'IV and V y'V respectively of Fig. 3;

Fig. 6 is a sectional View on line VI--V of 1iig'. 2; Fig. a sectional view on line VII- Vfl of Fig", 3; lFig". 8 is a View similar to Fig. 7 under diferent'load conditions; perspective, view of one embodiment of c'r'ofssrr'l'elrib'er fory the carriage; Fig. 1 0' isa fragmentary sectional view longitudinally of'and at the end portion ofa glider, showing a different embodiment of sealing'meanstherefor;

ig". 1 1 is'anendview of th'esaid glider andl sealing means o f Fig'. 10;v 12 'is "a frag rr`1leri'tary plan similar to Fig'. 2, and showing ai modified embodiment of cross-member'jjvFigs. 1 3 z i `n`d 14 are cross-sectionsV onv lines XII--XII and'XIV-f- XIV respectively of Fig 12; Eig; 1 '5'is" a' perspective'view of said modified embodir'rent of`c'rossrriembe`r; Fig. 1 6 is a longitudinal ele'va'tio'-r'1I of a part'off a1 rail and glider `ti'li'zing'modified construction of anti-friction nieansjtlierebetween;

Fig. 17 is" a' cross-section on line Fi's 1`6;', i 18' S h'eet" 1)'is' a cross-sec of ar 'lan' 'glldifj with" a t't`a `cl`1'e d'y rossmember, and' shovvirig meris for retaining the glider and cross-member assembled;" Figi' 19, 20'y and 21v are perspective views` of, hr'ee' filither moditie'd' constructions of' crosslme'mbe'rsf'y Figl 22"i's a perspective fragmentary'vievv o'f tlie" Web element utilized in the modification of Fig, 21;'

Fig. 23 isa' plan of a modified embodiment o'fsu'pport; Fig. 24' is a sectional view longitudinally ofV a'piston and" cylinder'-actuating means of Fig. 2'3`, taken" ori line XXIV-XXIV thereof; i Fig. 2:5 Aisa'section'al view similar to'Fi'g. 2'4 and shovv'- ingfadoublelended cylinder; Fig; Z6'i`s a' sectional 'la'nj of Fig'.' 25; arid As'A on arbitrarily selected one' pliiiea'tion the in' en# tion' in one use thereof the general organization'of-l2ig 1 illustratsan'electric motor 3i)vdriving? any desiredV iri'f strument'lifyf 31 through' the' agency' of a',belt and pulleys a'nd3-4` respectively'on the shafts o`fj said motor i 'instrumentality'. While it is intended that 'the 'support "described may be used in 'conjunction withfa Avariicii pllle'y, it mail alSol beused"l to maintain belt n applications Where'both'the driving and'L driven pull s' have fixed diameters. In' the lattfe'r circumstanoe the sprln'giis" provided in the support' o f the present invenl tiori'ii' thev former', the springY is inthe variable pitch pulley and movement ofthe `carriage is by direct contred tio'n, by' the screw` or Aecpl'iv'alen't means, for' movement `hecarriageboth forwardlyand vrearwar`dly. An exl le'fof' direct connection foi movement both ways and retention of the cariiage'at' the position to whili it s moved is included! herein with thefshowingifofkEigs; 25;"27', and figures j prior thereto show tliecarrioge 'as mfea'n's in the" support for keepingy th'e belt'nder fol-"u sewith fixed' diameterpulleys. Irlgeneral, "isl representative' vof' a Vmovable or adjustable 'i'al -footnrofofftho' present' 'iinontionv resido; in 1 otojnlof'a snppoit s 'slfontlie (said inoolionisin As shown; a be'd 36`is' provided to` which the lixed instrumentality is secured, and to which a xed portion of the support of the present invention is also secured, it being understood that said bed is representative of any structure, such as oor, table, wall, shelf, ceiling, or the like which will alord relatively fixed mounting for the aforementioned fixed instrumentality and fixed portion of the support. v

The xed portion of the support as herein illustrated, comprises two parallel rails 37 the ends of which are made fast to transverse cleats 38 which may conveniently be formed from appropriate lengths of angle iron one flange of which forms a foot juxtaposed to and adapted to be secured to bed 36 and the other flange of which stands perpendicularly and constitutes an end abutment and rigid support for the said rails. The assembly of rails and cleats forms a rectangle of which the cleats will arbitrarily be referred to as at the ends and the rails as at the sides of the rectangular assembly constituting the ixed or basal portion of said support.

The movable portion of the support comprises a carriage 39 having slidable movement longitudinally of the rails, said carriage having gliders 40 at its opposite side margins cooperating with the rails to not only provide for sliding of the carriage on the rails but to also keep the carriage assembled upon said rails. Each glider is conveniently comprised of rectangular or square tubing the inside diameter of which is greater than the diameter of the rail which it envelops.

By the use of a cylindrical rail within rectangular or square tubing, there will be a space between the adjacent or meeting walls at each corner of the tubing and the cylindrical face of the rail, and the portions of the Walls and rail dening that space may betermed and function as a receptacle or raceway 41, in general terms, which may be considered as comprised of an outer raceway formed by the tube walls and an inner raceway formed by the rail surface toward each corner of the tubing.

Antifriction means are provided between the rails and the said gliders or tubes, and in one embodiment of the invention, balls 42 are introduced into and retained in said raceways as illustrative of such antifriction means. The carriage 39 has a limited longitudinal movement, the range or amplitude thereof being conned approximately to the difference between the length of the rail and length of the tube or glider. In order for the balls to function as intended, that is, to roll in the raceways and thereby permit the tubes or gliders to move freely for their allotted amplitude longitudinally ofk the rails, it is essential that the raceways or receptacles be not filled with balls for their entire lengths. The length not having balls may be called for convenience the void length of the race, and this void length need not be more than one half of the distance it is intended the tube will travel.

lesser number of balls would of course reduce the loadcarrying capacity and would afford support beneath a less length of the carriage.

For nicety of action, it is important that four sets of balls be provided in each tube and rail assembly, that is, one set in each corner of the tube, and also that they have a reasonably good tit so the tube does not have any material lateral movement with respect to the rail. It is furthermore within the province of the present invention to preload the balls, that is to say, the race is made tight for the balls so there will be pressure applied to the balls before addition of the load to be carried by the carriage. This assures contact of all of the balls with the race so that all will roll and none will merely slide along.

Where economy is a factor, andi-,the anti-friction quality of a linear ball bearing is not imperative, cylinders or rods 43 (Figs. 16 and 17) practically the length of the tubes may be inserted in the receptacles or raceways above described, instead of balls. Use of rods or cylinders in the receptacles or races has its highly practical aspects. The size of commercial steel tubing is determined by its outside diameter and the wall thicknesses, less than @i6 of an inch usually being given in terms of Stubs gage, and having the following equivalents in decimal parts of inches, viz:

11 ga.=.120 12 ga.=.109 13 ga.=.095 14 ga.=.083

Commercial sizes of round linished steel are usually by sixteenths of an inch. Consequently, it would be almost impossible to choose from commercial materials a rail and a tube that would t well. Whereas, after rst determining the rail diameter required to withstand a given stress, it is possible to ascertain a tube and ball or tube and rod combination that will provide a reasonably good fit. Balls come in multiples of 374,2 of an inch. Round steel, in small sizes, such as would be used in the races of the riders, comes in multiples of 1&4 of an inch. Drill rod in millimeter sizes is also obtainable. Because of these available sizes, the simplest arrangement is to employ rods as the antifriction means. The rods may have a length equal to that of the tube in which located; the sliding of the glider on the rail takes place with the line contact of the rod on the rail. In any particular mounting of the support, as on floor, side wall or ceiling, two of the rods in each glider will make line While the use of antifriction means, such as balls in an annular race, is a matter of common knowledge, yet it is recognized that the balls in that type of race have a continuous or non-ending path enabling the movement to be cyclic so all of the balls can roll without interruption, and therefore poses no problem. But in the support f of the present invention, the path of the balls is linear, and hence the total amount of displacement is subject to limitation.

Since the normal displacement of the balls along the rail will be practically equal to one half of the displacement of the glider, and since the displacement of the balls along the glider will be closely equal to one-half the displacement of the glider, but in a direction opposed to the direction in which the glider is displaced, a suicient void or space lengthwise of the race is provided to enable the balls to roll without interruption for the full displacement of the glider on the rail between the limiting stops. Just enough balls are included within each race in proportion to the maximum travel distance of the glider to permit them to roll uninterruptedly and at the same time afford maximum load-carrying capacity for the carriage. A

contact with their rail and carry the weight of and support the carriage and motor.

If so desired, the rods may be made shorter than the glider tubes so as to leave voids in the raceways, so the rods will float much the same as the series of balls, thereby enabling some sliding to occur between the glider walls and the rods and some between the rods and the rail.

Operation of the carriage, both to change its location and provide the required belt tension may comprise, as shown in Figs. 1 to 4, a worm or plurality of worms 44 parallel to and between the rails and with the ends of the worm projecting through the end cleats 38. One end of the worm is provided with a nut or other means 45 pinned or fixed thereon, which constitutes an operating means and also a means for preventing longitudinal ydisplacement of the worm in a rearward direction away from the nut. The other end of the worm is shown provided with a nut 46 pinned thereon which prevents site sides of the worm. Since vthe .worm is preyented from displacement longitudinally, rotation thereof obtains .shifting of the yoke forwardy or rearwardly in accordance with .direction of rotation .of the worm. The directions of forward .and rearward are .arbitrarily used herein to designate ,movement toward `or away Vfrom the instrumentality driven by the motor, being carried jby the support.

The `carriage body as herein illustrated comprises two cross-members the end margins .of which are secured Ato the two gliders. One of .these .crossmeinbers 49 is secured at the .rear .end `regions of 4the .gliders fand 4provides means for attachment ofthe rear .feetof the motorzthereto, and the other crossmember50 is adjustable, l.to .agree with ytne front-to-back :foot spacing of the .applied motor, .and provides means for .attachmentof the forward feet of the motorthereto. yThough .the ycross-members may .be variously constructed, each .provides a part .or webSJ. crosswise of and having free passage for the worin :44 therethrough, n.and the'rebyuone member, here .shown as the yrear `one 49, provides means for engagement-by .the rear en d of .a spring 52 thereagainst,` saidY spring .being Amounted on the wor-m Ivand extending .forwardly to .the aforementioned yoke. lOperating the yoke tof-'compress the spring will thereby apply Ytension to .the driving "belt between'the motorand driven instrumentality. Y

The particularconstmction of cross-members as shown in Figs. 2 to l9, each comprises a metallic A.channel with parallel longitudinal -anges 53 connected each 'to the other at one longitudinal edge of'eachby alongitudinal web 51 which has been referred to above las lthe web through which the worm passes. Said'web `has less-length than the flanges, the web length ybeing just sufficient to admit jit lengthwise in the space between and perpendicular to the gliders 40. The flanges, fhowever, overlap and project atvtheirrends beyond' the gliders, thednenlsions `of `the web and Agliders related sothat Veach glider will just t between the pair of flange ends of the :cross-member. Y y i `Bolts 54 extending from one flange to the other in vicinity of .theglider provide clamping means `for *securing the member to the glider. Asshown, one bolt n54 is next the inner side of the glider and next the edge of the flanges opposite from `the web, andtwocb'ollts are .shown at theouterside of the Xgliderand next the'opposite corners of the angesf These last-mentioned 'bolts will, in practice, draw theends of .the pairs of flanges ltoward each other and in'eect create a 'trapezoidal .com figuration which will prevent inward .displacement .of vthe cross member. However, to prevent tightening .said bolts .to ,such V extent that .the glider would 'be deformed, suitable .limiting means may be provided such as sleeve 55 on the single bolt v54 s'panningclip '5 6 on the pair of lbolts, having dimensions between flanges slightly less than the dimension of the glider. It may also be mentioned in this connectionthatlsleeves .5.7 forthemoytor-attaching bolts may also be Yprovidedto v.preventfdistortionv of the iianges -or lessening of theiiange spacing when those .bolts are tightened in mounting the lmotor. Outward displacement of the .member isvlimited `by engagement ofthe end of theweb with the gliderrather Vthan by .engagement of the bolts or sleeves thereon with thefglideras in Fig. 8.

' vBoth as anaidin assembly and to maintain p erpendicularityof the cross-members .on the gliders, each glider .preferably has a lug or stop .at its inner side, said lug-rbeingaccurately ,located to engage againstthe zside oflsleeve .on theinner bolt .S4 of one cross-member 4.9, the lugs-on the `two-gliders.both .beingpositioned to function in conjunction with the same cross-member. Thus the lugs are provided -only for the ,non-adjustable .crossfmember .so adjustment of vthe lother .member to -proper position as :requiredby motor r:foot spacing, will vnot-be.hamper.ed. Meansmay be provided ifor retaining a.1ubricant,.such

as .oi-l .or grease, .within the tubular glider in the races thereof, andmto exclude dust. As shown-.more espec ally -in Eig. 7V, .a .felt washer or other'pad S9 is applied around the rail and at the end of .the tubular A.gliderf 'Aber or other washer .60 is located .against the endl @offtle glider to substantially close `lthe .end ,opening thereof around the rail'and the said .pad is .contained a'fcap y61 which contines it in the regionwithinlthe .cap next said washer. The cap may be held in ,place by snapping over stud heads x62 or other lprojections'.p rovidiec'l for the purpose on the outer margin of .the glider. The washer constitutes a convenient means,'likewise, lforflfetaining vballs 'from escape vat the ends of the races. It is desirable .to avoid jamming Vthe -caps .6I between the ends ofthe gliders .40 andthe .cleats'3f8` carrying .the rails when the gliders come .to v.theendsof .their recipie- Lcable path of movement .on the rails. -Thisdesideratum can be accomplished byVv including stop .meanson .the worm d4, .in `exemplification Yofv'w-hich -a .pair .of nuts .53 are shown `next the inside faceof the upstanding harige of one cleat 38 and engageable by the .approaching face of vthe carriage cross-member web 51'; ytheotherend Lof the worm has a sleeve or'nut .6 4'thereon .serving the same purpose `between `the adjacent cleat and carriage. A modified lconstruction fro-m that shown .in sFigQ 7 for the ball and `lubricant vretaining and `dust .excluding vmeans Yis shown in Figs. 1.0Iand ll. vIn .this instence a washeror pad 59a is provided which tits within .the .glider -next'the end thereof, .this washer also .having .a vcentral opening to admit passage ofthe rail therethrough. Said washer is properly `prrnaortioned to make closure contact .atits outer periphery with the interior `faces vof theseveral walls of the glider and to .make .closure contact at the periphery of its opening with .the Youter.circurnference of therail sogas to fully seal lubricant .within .the glider and exclude dust from entry Vinto .the glider.Y :While ,various materials may be Aused toy compose xsaid washer,

it is desirable `to .employ one which yis rigidor'sernirigid, for instance, o f the nature of hardrubber, of .which a .synthetic material available on the market .under the trade name of Neoprene has provedvery satisfactory. Said washer .59a .may be retained in its as sembledlocation Lin the Iglider by meansof vfour screws `62a introduced at the corners thereof throughthe several walls @fthe glider. Presence of the washer in the rider Yretajnstheballs ,or other antifriction means from vundesired .displacement and theproximity of the screws 62a to the line of travel ofthe .antifriction means obtains a solid stop for the Said antifriction means. The heads of `said screws preferably yprotrude from the .outer surfaces of the tubes .comprising the IJliders .and serve the further purpose of stops` f. r location means for the mounting of the crossfrnernber anges on the riders, eliminating necessity-for inclusion of the specific lugs 58 previously described inconnection with Fig. 7, said screw heads performing .the .function of said lugs. Y i

For use with larger or with more .powerful motors', a more substantial cross-member may be found necessary or desirable, such as the one illustrated in-FigsflZfto l5. Essentially said cross-member of this showingcorresponds to .that previously described, but .utilizes .two channel members .e5 the webs. 66 of which are', with space between, parallel to each other, .and the flanges .67 vvof which are directed away from Aeach' Aother .with'thepair of toprflanges in a common Aplaneandthe vpair.oflower flanges in .a common plane. The -pair of top .hanges .are secured, as .by welding, to .a plate' 68 overlying yboth tianges and spanning the Vgapl .between thechannels. similar plate 63 underlies and spans .between .thelbottom pair of anges and is welded or :otherwisegSecu-red thereto. The `channels .and plates thus assembled .cnstitute ani-beam yoffwhich the webis hollowiandmonstituted by the spaced websof the channels. Th ends of 1the flanges, ;as before, togethenwith thefends 'of. said .plates :68, project beyond f theendsuof lthe webs [an .may

therefore be similarly dellected to trapezoidal relation in attachment to the gliders.

As with the previously described construction, and similarly as an aid in assembly and to maintain perpendicularity of the fixed cross-member on the gliders, each glider has a lug or stop 58 at its inner side, with which the web of the xed cross-member engages.

The top and bottom plates 68 of the cross-member of Figs. 12 to 15, are provided with appropriately related slots 70 registering with the gap between webs 66 to accommodate bolts for attaching the motor. The Webs also yhave properlyv located holes therein'for passage of worm 44 and rods 43 above described. The construction of worm, operating means, yoke and associated parts may be duplications of those heretofore described, except that the stop sleeve 64a on the worm in this instance is longer than in the previous showing so as to reach the web 66 which now is located at the inner edges of the flange. ln each construction, the worm 44 is shown with a spring 52 thereon, said spring being compressed between the yoke 47 at the inner end of the spring and the web of the cross-member. Also in each construction, it is preferable to provide a spacing sleeve 71 on the worm at the part thereof traversing the space between the yoke and the other cross-member opposite from the one engaged by the spring. This spacing sleeve 71 will both limit retraction of the yoke in the carriage and will also enable positive retraction of the carriage to be effected by appropriate turning of the worm, when so desired, as for instance when it would be necessary to displace the motor toward the instrumentality in order to change a group of V-belts more readily. Said spacing sleeve 71 is preferably flexible, instances of which are rubber or combination of rubber and fabric.

locating lug 58 on the glider to be the only possible means for effecting proper location and perpendicularity of the cross member on the glider. For instance, in Fig. 18, an alternative means is illustrated and constitutes a locating or positioning screw 72 the shank of which passes through one flange 53 or other part of the cross-member where juxtaposed to the glider, and screws into the glider wall. The flange is slotted for reception of the screw, as at 73, for enabling the glider and cross-member to be adjusted to perpendicular relation before clamping.

Furthermore, other assemblies to provide flanges and. webs may be utilized in construction of members than the ones heretofore described. For instance, in con-4 sidering the modification of Figs. 12 to 15, it is within the scope of the present invention to utilize the plate ends` as the entire trapezoidal clamping end of the crossmember without extending the flanges of the channels to accomplish this feature of gripping engagement. This proposal is illustrated in Fig. 19. The channels i4 therein shown have their webs 75 parallel and spaced and of correct length for location from glider to glider just as heretofore described for the webs of the preceding figures. The flanges 76 of these channels are, however, of just the same length as the web. The said ilanges are welded or otherwise secured to plates 68 which projects beyond the web and anges, and the projecting ends of lthe plates are adapted to be juxtaposed across and grippingly bolted with trapezoidal deflection on the gliders.

As a further modification within the inventive concept hereof, an additional web may be provided for each channel, which in eifect utilizes two rectangular tubes 77 as shown in Figs. in place ofthe open channels of Fig. 19. By this construction, four vertical webs 78 are provided.

`These webs, in pairs, have flanges 79 in common, thereby resulting in the aforo-mentioned rectangular tubes. Plates 68 are welded or otherwise secured to these flanges '79 'j in like relation to the plates, flanges and webs of previous- 'appreciated that a further modification may provide a pair of webs 80, as in Fig. 21, with flanges 81 in common to the said pair of webs as the body structure interposed between two plates 68. In this instance, the ends of the flanges 81 are slotted, as at 82, with those slots in registration with the motor-bolt slots 70 of the plates, one of the slotted ends being shown in Fig. 22 before attachment of the plates thereto which is done subsequently as by welding the plates to said flanges.

An additional feature of the invention, is the provision of fluid actuation of the carriage as exemplified in Figs. 23 to 27 inclusive. For illustrative purposes, the general rectangular base construction of Figs, 1 to 4 is arbitrarily selected for the showing of this additional feature, so it is to be understood that various parts previously described, inclusive of rails 37, cleats 38, gliders 40 and antifriction means therefor, cross-member 49 fixed on the gliders and cross-member 50 adjustably secured to the gliders may be used and previous description thereof will suflice.

Referring specifically to Figs. 23 and 24, cross-member 49 of the carriage which has its relation to the gliders 40 Xed by lugs 58, has a fluid-pressure cylinder 83 secured thereto and located parallel to and medially be,- tween said gliders. Said cylinder has its closed or head end next the web of said cross-member and secured thereto, as by a threaded neck 84 projecting through the web and secured by a nut 85. Said neck is hollow and has a pipe-fitting 86 threaded thereinto, said pipe-fitting being representative of any appropriate connection to a source of iluid pressure. Within the cylinder 83 is a piston 87 from which a piston rod 88 projects to and through the opposite or adjustable cross-member, which acts as a guide therefor, and to the cleat 38 therebeyond. That cleat has a bracket 89 thereon in opposition to the end of the piston rod, and is preferably provided with a hollow seat or socket for the end of the piston rod. As fluid pressure is introduced into the cylinder, the piston rod seats in the socket of the bracket and the carriage is moved in a direction away from the bracket, thereby functioning to apply a tension on the belt. Release of the iluid pressure will permit the carriage to move in the reverse direction, for instance thereby relieving the tension in the belt between the motor and driven instrumentality.

lf desired to actuate the carriage in both directions with fluid pressure, a double-ended cylinder may be employed as shown in Figs. 25 to 27 inclusive. According to this embodiment, cylinder 91 has a closure or head 92 at one end and a piston rod 93 projecting through a stufling-box closure 94 at the other end. A piston 95 on the inner end of the piston rod can reciprocate between those end closures by introduction of lluid pressure at either end through pipe fittings 96 connecting with a three-way valve 97 and source of iluid pressure. The valve admits pressure to one end of the cylinder and releases the pressure from the other end.

Since the piston rod exerts alternatively push and pull, the bracket 98 therefor at the cleat 3S, is shown bolted to the cleat and as having a swivel connection 99 with the piston rod. The cylinder head also preferably has a swivel connection 100 with a stud 101 projecting through the cleat 38 next that end of the carriage, said stud being secured by nuts 102 thereon and projecting beyond the web of the cross-member to constitute a safety stop for movement of the carriage toward the cleat.

This last-described double-acting lluid piston arrangement is intended primarily to vary the distance between the motor and the instrumentality and then to maintain such distance to thereby effect and maintain whatever speed ratio of drive for the instrumentality desired. Said instrumentality is, therefore, in this arrangement, equipped with a variable pitch pulley.

While the present showing illustrates the invention in its more simple embodiments, it is to be understood that the number of rails and gliders is not restricted to the arbitrarily selected embodiment, and representation of wagens two? rails and two gtide'rs is illustrative of the Broadcomcept of a plurality of rails and gliders havingth'e' load stress directly thereover. Consequently, thev invention contemplates constructionv of supports for movably mounting mechanisms of relatively' light weight, such as several pounds, upto'mechanisms' of great weight of a toiilor more'.

f claim':

1. A support comprising parallel rails, rectangular tubular gliders on said rails, said gliders having parallel side' walls' longitudinally of saidrails keeping the gliders from sagging, and a webbed cross member extending between said gliders and overlapping said side walls of the gliders with ends of the web of the cross member substantially in engagement with said side walls of the gliders whereby the gliders are prevented from twisting on the rails and distribute weight applied to the cross member over extended lengths of the rails.

2. A support comprising parallel rails, tubular gliders on said rails, and a webbed cross member extending between and overlapping said gliders with the ends of the web of the cross member substantially in engagement with said glider, and interengaging stop means projecting from the glider and cross member for locating the cross member in perpendicular relation to said gliders.

3. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on the rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, cross members between the gliders having rigid attachment thereto whereby weight applied to said cross members is distributed over an extended length of the glider without twisting or bending the glider, antifriction means in the gliders7 closure means at the ends of the gliders for retaining said anti-friction means and lubricant in the said gliders, and stop means for the carriage projecting inwardly toward the carriage between the rails and interposed in the path of movement of the cross member to engage and limit movement thereof with the ends of the gliders and closure means thereon still away from the ends of the rails.

4. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on said rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, and webbed cross members extending between said gliders, said webbed cross member comprising a channel having flanges in planes parallel to said rails and gliders, said web extending in its lengthwise direction crosswise of the gliders to span the space between said gliders, said flanges having greater lengths than the webs at both ends of the webs and overlapping said side walls of the gliders with the ends of the webs of the cross members substantially in engagement with s'a-id side walls of the gliders whereby the gliders are prevented from twisting on the rails and distribute weight applied to the cross members over extended lengths of the rails.

5. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on said rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, and cross members extending between said gliders, each sa-id cross member comprising a web extending in its lengthwise direction crosswise of the gliders to span the space between and perpendicular to said gliders, said cross members having a plate perpendicular to the webs longitudinally overlying the same and xed thereto, said plate having greater length than the web at both ends of the web f each said cross member and overlapping said side walls of the gliders with the ends of the webs of the cross members substantially in engagement with said side walls of the gliders whereby the gliders are prevented from twisting on the rails and distribute weight applied to the cross members over extended lengths of the rails.

6`. A support comprising parallel rails and a carriage i'ovably"'niounted" thereon, said carriage having rectangujlar tubular'gli'ders on`V saidi rails, said gliders liavingfparallel side walls longitudinally of said rails keepingthe` gliders fromv sagging, and cross members extending between said gliders, each cross member comprising al plurality of parallel webs extending lengthwise between and perpendicular tothe gliders with the ends of the webs of the cross members substantially ink engagement with said side walls of the gliders whereby the glider are prevented from twisting on the rails, said cross members having a plate perpendicular to the webs longitudinally overlying the same and fixed thereto, said plate having greater length than said webs at both ends of the webs and overlapping the side walls of the gliders in engagement with the gliders .to thereby distribute weight applied to the cross member over extended lengths of the rails.

7. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on said rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, and cross members extending between said gliders, each cross member comprising a plurality of spaced and parallel webs having flanges at the longitudinal edges thereof extending away from the space between the webs, said cross member having a plate flatwise on said flanges overlapping said side walls of the gliders with ends of the web of the cross members substantially in engagement with said side walls of the glider whereby the gliders are prevented from twisting on the rails and distribute weight applied to the cross members over extended lengths of the rails.

8. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on said rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, and cross members extending between said gliders, each cross member comprising a tubular structure perpendicular to and extending longitudinally across from one glider to another glider with the ends of said tubular structure substantially in engagement with said side walls of the gliders whereby the gliders are prevented from twisting on the rails, and said tubular structure having a plate secured thereon, said plate having greater length than said tubular structure and overlapping said side walls of the gliders whereby weight applied to the cross members is distributed over extended lengths of the rails.

9. A support comprising parallel rails and a carriage movably mounted thereon, said carriage having rectangular tubular gliders on said rails, said gliders having parallel side walls longitudinally of said rails keeping the gliders from sagging, and cross members extending between said gliders, each cross member comprising a pair of plates with one plate overlying and the other underlying at their ends the said gliders, and comprising a tubular web structure medially between longitudinal edges of said plates secured to both said plates and extending from one glider to the other substantially in engagement with said side walls of the gliders whereby the gliders are prevented from twisting on the rails and distribute weight applied to the cross member over extended lengths of the rails, and said tubular web and plates having registering slots therein adapted to pass bolts adjustably therethrough.

10. A support comprising parallel rails, rectangular tubular gliders movably mounted on said rails, the wells of said gliders extending longitudinally of the rails, two walls of each glider being substantially parallel and constituting side walls thereof, and both said side walls of both gliders being substantially parallel to each other, an integral cross member comprising upper and lower portions each extending from one glider to the other and extending at each end thereof over both said side walls of both gliders and juxtaposed in flatwise surface contact with `the remaining Walls of each of said gliders, and means to each other.

References Cited in the file of this patent UNITED STATES PATENTS 132,803 Clarke Nov. 5, 1872 12 Jackson Ian. 1, 1884 Wood Feb. 2, 1892 Richards May 17, a1898 Dilks Oct. 1, 1929 Harris Sept. 20, 1932 Berndt Apr. 9, 1940 Koch Feb. 20, 1945 Thomson May 30, 1950 FOREIGN PATENTS France Dec. 30, 1936 

